We couldn't find a cover to fit our 2015 4200. I found out that the ADCO company would make us a custom cover. They sent a measuring sheet and we had to measure the distances between the air conditioners. If I remember correctly, there were some other measurements we had to take and write down. The cover has zippers so we can access both the kitchen door and the toy hauler (back) door, plus zippers on both sides of the drop-down back door. It's a very nice cover; has some kind of soft fabric on the inside and reinforced at the stress points.
We only cover it in the winter...........when we take it off we literally stuff it into a 50 gallon trash container. It takes work, but we get it in there and can get the lid on it.
It was a bit pricey, but when you cannot find anything "ready made" you have to do what you have to do.
This is their website
www.ADCOProd.com
If you have any questions, please ask and I'll try to answer them.
Ivan/Anna Zettle